This invention relates to a textile machine comprising a plurality of drafting units arranged next to one another in a row. Bottom cylinders of the drafting units, which extend through in the longitudinal direction of the machine along several or all drafting units, are disposed at bearing points which are arranged at a distance from one another.
In the case of textile machines comprising drafting units which are disposed next to one another, the bottom cylinders are normally designed in such a manner that they continue in the longitudinal direction of the machine along several or all drafting units. The continuous bottom cylinders are disposed at several bearing points which are arranged in the longitudinal direction of the bottom cylinder at a distance from one another. As a rule, the bottom cylinders are composed of several segments which are connected with one another at the bearing points by means of bottom cylinder couplings. For the bearing of the bottom cylinders, roller bearings are used which are accommodated at the bearing points in roller stands which are connected with the machine frame and are in each case provided at the distance of several drafting units. The delivery bottom rollers are rigidly, that is, radially unslidably, disposed at the roller stands, while the bearings or bearing receiving devices for the bottom cylinders disposed in front of the delivery bottom cylinder are guided at the roller stands in one rail respectively which extend transversely to the longitudinal direction of the machine and permit an adjusting of the distance to the respective adjacent bottom roller. An arrangement of this type is illustrated and described, for example, in the German Patent Document DE-OS 35 32 555.
It was found that the continuous bottom cylinders do not have a straight course along their whole length. These deviations in the radial direction may result in tensions mainly in the area of the bearing points and of the connecting points of the segments of the delivery bottom cylinder. Although it would be possible for the elimination of these radial deviations to adjust the height of the machine frame at different points of its longitudinal dimension, such an adjustment of the machine frame would also affect the position of other machine parts. Such an adjustment will also not be useful if the radial deviations in the case of the delivery bottom cylinder are based on variations in dimensions in the case of the roller stands themselves or in the case of the machine parts supporting them. In this case, deviations may, for example, be the result of nonlinear longitudinal supports on which the roller stands are held, or of manufacturing inaccuracies in the case of the roller stands. If the roller stands are each held by several longitudinal supports, slight deviations in the case of each longitudinal support may add up to a considerable deviation of the bearing positions for the delivery bottom cylinders in the case of the roller stand. This may then have the result that the bearings for the delivery bottom cylinders may no longer rest with a close fit in the bearing receiving devices of the roller stands.
For solving the above-described problems, it has been suggested to arrange the segments of the bottom cylinders cardanically movably at the connecting and bearing points (German Patent Document DE-PS 12 92 557 and British Patent Document GB-PS 982 878). However, in the case of this arrangement, the radial deviations themselves cannot be compensated; on the contrary, the problems are only to be reduced which occur as a result of the radial deviation. In addition, the suggested construction has the disadvantage that considerable constructional expenditures are required with respect to the design of the bearings and of the couplings.
It is an object of the invention to provide a method of construction in which radial deviations are compensated at the bearing points of the continuous delivery bottom cylinder.
This object is achieved in that, in the case of the delivery bottom cylinder, at least some of the bearing points are radially adjustable.
By means of the construction according to the invention, the advantage is achieved that, when the roller stands and the supporting elements accommodating these roller stands are manufactured and arranged, no narrow tolerances must be maintained. Even when the position of the bearing points for the delivery bottom cylinder depends on several inaccurately manufactured and inaccurately arranged structural elements of the machine frame, this inaccuracy can easily be compensated by the adjusting of the bearing point in the radial direction according to the invention. The delivery bottom cylinders may be precisely aligned in the longitudinal direction of the machine so that the segments are in alignment with one another along the whole dimension of the delivery bottom roller. However, it may also be sufficient to only roughly align the bearing points and to accept slight radial deviations. In any case, by means of the radial adjustability in the case of the bearing points, it may be achieved that the bearings rest in the bearing receiving devices with a close fit and that tensions are avoided.
In an advantageous development of the invention, not all bearing points in the case of a delivery bottom cylinder are designed to be radially adjustable. At a distance of at least one radially adjustable bearing point, one bearing point respectively which is not radially adjustable may be arranged in the case of the delivery bottom cylinder. The non-adjustable bearing points may preferably be provided at such points in the case of the machine frame which are determined with a relatively high precision with respect to their position in the case of the machine frame, such as at positions with a perpendicular connection of the machine frame with the floor of the spinning room. The adjustable bearing points may also be aligned according to the position of the non-adjustable bearing points, in which case an adjustment with slight radial deviations is easily possible.
The adjustable bearing points may be designed in such a manner that the bearings proper may be displaced and adjusted inside bearing receiving devices. Instead, it may be provided in an advantageous further development of the invention that the bearings are rigidly fastened in bearing receiving devices and the bearing receiving devices are arranged in a radially slidable manner.
In an advantageous development, the bearings or the bearing receiving devices are fastened at the bearing points on holding devices which are connected with the machine frame at a distance of several drafting units. As a rule, it is not required to dispose the continuous delivery bottom cylinder behind one drafting unit respectively. Roller stands are expediently used as holding devices which receive the bearings for all bottom rollers of the drafting units, thus for the delivery bottom roller and the slidable bottom rollers which are disposed in front of this delivery bottom roller.
In an advantageous further development of the invention, the holding devices are fastened to at least one longitudinal support of the machine frame. As a result, a constructionally simple connection is obtained between the holding devices and the machine frame. In this case, the longitudinal support or supports rest on perpendicular supports of the machine frame at a distance of at least one holding device. Variations in the dimensions of the longitudinal supports, particularly deflections, may have the result that the bearing receiving device for the delivery bottom cylinder in the case of one holding device is in a different position than in the case of the adjacent holding device. The holding devices which are arranged in the proximity of the perpendicular supports of the machine on the longitudinal support or supports are relatively exact in their position. If several longitudinal supports are used for the fastening of the holding devices, the deviations in the case of the holding devices may add up under certain circumstances. Particularly in this case, the radial adjustability of the bearing points at the delivery bottom rollers is very suitable for the compensation of the relatively large deviation.
In an advantageous development, the hinges for the loading arms of the drafting units are arranged on one of several longitudinal supports so that this longitudinal support has a double function.
It is advantageous to provide the longitudinal support or the longitudinal supports with the shape of a cylinder or a hollow cylinder.
In an advantageous development, the slidable bearing receiving devices are provided with contact surfaces by means of which they rest against mating surfaces, which are connected with the machine frame, and can be fixed in an adjusted position by means of fastening devices. In this case, the mating surfaces are advantageously arranged on holding devices which, in turn, are connected with the machine frame. The slidability of the bearing receiving device along a mating surface permits a simple and reliable adjusting of the bearing receiving device.
It is advantageous to provide screws as fastening devices which are arranged perpendicularly with respect to the contact surfaces and the mating surfaces. In this case, the screws and/or the contact surfaces can be moved in the radial direction of the delivery bottom cylinder relative to the mating surfaces. As a result of the relative mobility, the bearing receiving devices may be displaced in the radial direction of the delivery bottom cylinder and may be fixed in the displaced position in that the contact surface is screwed to the mating surface.
It is advantageous to arrange the contact surfaces and the mating surfaces at least approximately perpendicularly with respect to the axis of the delivery bottom cylinder. The contact surfaces and the mating surfaces will then extend essentially in the same direction as the radial planes of the delivery bottom cylinder, whereby a good slidability and adjustability becomes possible.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.